<template>
  <div class="login_container">
    <div class="login_box">
      <!-- 头像区域 -->
      <div class="avatar_box">
        <img src="../assets/img/兔子.gif"
             alt="">
      </div>
      <!-- 登录表单区域 -->
      <el-form :model="loginForm"
               :rules="loginFormRules"
               ref="loginFormRef"
               class="login_form"
               label-width="0px">
        <!-- 用户名 -->
        <el-form-item prop="username">
          <el-input v-model="loginForm.username"
                    prefix-icon="iconfont icon-user"></el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
          <el-input type="password"
                    v-model="loginForm.password"
                    prefix-icon="iconfont icon-3702mima"></el-input>
        </el-form-item>
        <!-- 按钮区域 -->
        <el-form-item class="btns">
          <el-button type="primary"
                     @click="login">登录</el-button>
          <el-button type="info"
                     @click="resetLoginForm">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      // 这是登陆表单的数据绑定对象
      loginForm: {
        username: 'admin',
        password: '123456'
      },
      loginFormRules: {
        // 验证用户名是否合法
        username: [
          { required: true, message: '请输入登录名称', trigger: 'blur' },
          { min: 3, max: 10, message: '长度在 3 到 10 个字符', trigger: 'blur' }
        ],
        // 验证密码是否合法
        password: [
          { required: true, message: '请输入密码名称', trigger: 'blur' },
          { min: 6, max: 15, message: '长度在 6 到 15 个字符', trigger: 'blur' }
        ]
      }
    }
  },
  methods: {
    // 点击重置按钮，重置登录表单
    resetLoginForm () {
      this.$refs.loginFormRef.resetFields()
    },
    // 点击登录按钮，验证表单，成功跳转
    login () {
      this.$refs.loginFormRef.validate(async valid => {
        if (!valid) return
        const { data: res } = await this.$http.post('login', this.loginForm)
        if (res.meta.status !== 200) return this.$message.warning('登陆失败')
        this.$message.success('登陆成功')
        /*
          1、将登陆成功后的token，保存到客户端的sessionStorage中
            1.1、项目中除了登录之外的其它API接口，必须在登录之后才能访问
            1.2、token只应该在当前网页打开期间生效，所以将token保存在sessionStorage中
          2、通过编程时导航跳转到后台主页面，路由地址为 /home
        */
        window.sessionStorage.setItem('token', res.data.token)
        this.$router.push('/home')
      })
    }
  }
}
</script>

<style lang="less" scope>
.login_container {
  height: 100%;
  background-color: #123456;
  position: relative;
  .login_box {
    width: 450px;
    height: 300px;
    border-radius: 3px;
    background-color: #fff;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    .avatar_box {
      width: 120px;
      height: 120px;
      border: 1px solid #eee;
      padding: 10px;
      border-radius: 50%;
      position: absolute;
      left: 50%;
      background-color: #fff;
      transform: translate(-50%, -50%);
      box-shadow: 0 0 8px #ddd;
      img {
        width: 100%;
        height: 100%;
        border-radius: 50%;
      }
    }
    .login_form {
      position: absolute;
      bottom: 0;
      width: 100%;
      padding: 0 20px;
      box-sizing: border-box;
    }
    .btns {
      display: flex;
      justify-content: flex-end;
    }
  }
}
</style>
